Imaging apparatus, control method, and storage medium for tracking an imaging target in a continuous shooting operation

Abstract

There is provided an imaging apparatus for continuously performing a plurality of photographing operations. The imaging apparatus includes an AF sensor and an image sensor. A microcomputer performs focal point detection (i.e., defocus amount calculation) processing based on a signal acquired by the AF sensor. Further, the microcomputer performs focal point detection processing based on a signal acquired by the image sensor. The microcomputer selects one of two focal point detection results and performs a control to drive a focusing lens in a lens drive 1 and a lens drive 2.

What is claimed is: 
     
       1. An imaging apparatus that continuously performs a plurality of photographing operations, the imaging apparatus comprising:
 a first image sensor configured to perform at least a first photographing operation and a second photographing operation successively to acquire a signal that can be used to generate a recording image, wherein the first image sensor includes a plurality of microlenses and a plurality of pixel portions each including a plurality of photoelectric conversion portions, wherein each of the plurality of pixel portions corresponds to each microlens; 
 a second image sensor, which is different from the first image sensor, wherein the second image sensor receives a pair of light fluxes of an image re-formed on a predetermined focal plane of an imaging optical system; 
 a focal point detection unit configured to perform first focal point detection processing and second focal point detection processing successively, wherein the first focal point detection processing is operated between the first photographing operation and the second focal point detection processing, and wherein the second focal point detection processing is operated between the first focal point detection processing and the second photographing operation, wherein the first focal point detection processing and the second focal point detection processing are calculation of defocus amount, wherein the second focal point detection processing is performed by calculating the defocus amount by using the focal point detection signal acquired from the second image sensor; and 
 a processor configured to control a first lens drive for driving a focusing lens based on a result obtained through the first focal point detection processing, and control a second lens drive for driving the focusing lens based on a result obtained through the second focal point detection processing, 
 wherein the first focal point detection processing is performed by using the signal acquired from the first image sensor in the first photographing operation, and 
 wherein the second focal point detection processing is performed by using a focal point detection signal acquired from the second image sensor, 
 wherein if an aperture value corresponding to the signal acquired from the first image sensor is equal to or less than a first aperture value, the processor controls the first lens drive based on a focal point detection result obtained through the first focal point detection processing. 
 
     
     
       2. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than the first aperture value, the processor controls the first lens drive without using a focal point detection result obtained through the second focal point detection processing. 
     
     
       3. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than the first aperture value, the processor controls the first lens drive based on both the focal point detection result obtained through the first focal point detection processing and a focal point detection result obtained through the second focal point detection processing. 
     
     
       4. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is greater than the first aperture value, the processor controls the first lens drive based on a focal point detection result obtained through the second focal point detection processing. 
     
     
       5. The imaging apparatus according to  claim 4 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is greater than the first aperture value, the processor controls the first lens drive without using the focal point detection result obtained through the first focal point detection processing. 
     
     
       6. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than a second aperture value, the processor controls the first lens drive based on the focal point detection result obtained through the first focal point detection processing. 
     
     
       7. The imaging apparatus according to  claim 6 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than the second aperture value, the processor controls the first lens drive without using a focal point detection result obtained through the second focal point detection processing. 
     
     
       8. The imaging apparatus according to  claim 6 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than the first aperture value and is greater than the second aperture value, the processor controls the first lens drive based on both the focal point detection result obtained through the first focal point detection processing and a focal point detection result obtained through the second focal point detection processing. 
     
     
       9. The imaging apparatus according to  claim 1 , wherein in the second lens drive, the processor performs the control in such a way as to drive the focusing lens based on both the focal point detection result obtained through the first focal point detection processing and a focal point detection result obtained through the second focal point detection processing. 
     
     
       10. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is equal to or less than the first aperture value, the processor controls the second lens drive based on both the focal point detection result obtained through the first focal point detection processing and a focal point detection result obtained through the second focal point detection processing. 
     
     
       11. The imaging apparatus according to  claim 1 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is greater than the first aperture value, the processor controls the second lens drive based on a focal point detection result obtained through the second focal point detection processing. 
     
     
       12. The imaging apparatus according to  claim 11 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is greater than the first aperture value, the processor controls the second lens drive without using the focal point detection result obtained through the first focal point detection processing. 
     
     
       13. The imaging apparatus according to  claim 1 , wherein if the second image sensor cannot capture an imaging target, the processor controls the second lens drive without using a focal point detection result obtained through the second focal point detection processing. 
     
     
       14. The imaging apparatus according to  claim 13 , wherein if an aperture value obtained when the second image sensor has acquired the signal is equal to or less than the first aperture value, the processor controls the second lens drive based on both the focal point detection result obtained through the first focal point detection processing and the focal point detection result obtained through the second focal point detection processing. 
     
     
       15. The imaging apparatus according to  claim 14 , wherein if the aperture value corresponding to the signal acquired from the first image sensor is greater than the first aperture value, the processor controls the second lens drive based on the focal point detection result obtained through the second focal point detection processing. 
     
     
       16. The imaging apparatus according to  claim 1 , further comprising a prediction unit configured to predict a future position of an imaging target with reference to a plurality of previously acquired focal point detection results,
 wherein the processor controls the driving of the focusing lens based on a prediction result obtained by the prediction unit. 
 
     
     
       17. The imaging apparatus according to  claim 16 , wherein the prediction unit predicts a future image surface position corresponding to the imaging target as the future position of the imaging target. 
     
     
       18. The imaging apparatus according to  claim 1 , further comprising a second image sensor configured to determine reliability of a focal point detection result obtained through the first focal point detection processing according to a reliability determination threshold value,
 wherein the second image sensor determines that the focal point detection result obtained through the first focal point detection processing is reliable if an evaluation value of the reliability of the focal point detection result obtained through the first focal point detection processing is greater than the reliability determination threshold value, and determines that the focal point detection result obtained through the first focal point detection processing is not reliable if the evaluation value of the reliability of the focal point detection result obtained through the first focal point detection processing is equal to or less than the reliability determination threshold value, and 
 the reliability determination threshold value is differentiated according to an aperture value corresponding to the signal acquired from the first image sensor. 
 
     
     
       19. The imaging apparatus according to  claim 18 , wherein a reliability determination threshold value to be set when an aperture value corresponding to the signal acquired from a first image sensor is greater than a first aperture value is greater than a reliability determination threshold value to be set when the aperture value is equal to or less than the first aperture value,
 a reliability determination threshold value to be set when the aperture value is greater than the second aperture value is greater than a reliability determination threshold value to be set when the aperture value is equal to or less than the second aperture value, and 
 the first aperture value is greater than the second aperture value. 
 
     
     
       20. The imaging apparatus according to  claim 18 , wherein if an aperture value is equal to or less than a first aperture value, the processor controls the second lens drive based on a focal point detection result obtained through the second focal point detection processing. 
     
     
       21. The imaging apparatus according to  claim 1 , further comprising a first determination unit configured to determine the aperture value at the timing the signal is acquired from the first image sensor. 
     
     
       22. The imaging apparatus according to  claim 1 , wherein the processor performs a control in such a way as to drive the focusing lens according to a control value acquired by weighting the focal point detection result obtained through the first focal point detection processing and a focal point detection result obtained through the second focal point detection processing. 
     
     
       23. The imaging apparatus according to  claim 1 ,
 wherein the processor controls the first lens drive during an interval between the first focal point detection and the second focal point detection, and 
 wherein the processor controls the second lens drive during an interval between the second focal point detection processing and the second photographing operation. 
 
     
     
       24. A method for controlling an imaging apparatus that includes a first image sensor configured to perform at least a first photographing operation and a second photographing operation successively to acquire a signal that can be used to generate a recording image, wherein the first image sensor includes a plurality of microlenses and a plurality of pixel portions each including a plurality of photoelectric conversion portions, wherein each of the plurality of pixel portions corresponds to each microlens and a second image sensor different from the first image sensor, wherein the second image sensor receives a pair of light fluxes of an image re-formed on a predetermined focal plane of an imaging optical system, the method comprising:
 performing first focal point detection processing and second focal point detection processing successively, wherein the first focal point detection processing is operated between the first photographing operation and the second focal point detection processing, and wherein the second focal point detection processing is operated between the first focal point detection processing and the second photographing operation, wherein the first focal point detection processing and the second focal point detection processing are calculation of defocus amount, wherein the second focal point detection processing is performed by calculating the defocus amount by using the focal point detection signal acquired from the second image sensor; and 
 controlling a first lens drive for driving a focusing lens based on a result obtained through the first focal point detection processing, and controlling a second lens drive for driving the focusing lens based on a result obtained through the second focal point detection processing, 
 wherein the first focal point detection processing is performed by using the signal acquired from the first image sensor in the first photographing operation, and 
 wherein the second focal point detection processing is performed by using a focal point detection signal acquired from the second image sensor, 
 wherein if an aperture value corresponding to the signal acquired from the first image sensor is equal to or less than a first aperture value, the processor controls the first lens drive based on a focal point detection result obtained through the first focal point detection processing. 
 
     
     
       25. A non-transitory storage medium storing a program that causes a computer to control an imaging apparatus that includes a first image sensor configured to perform at least a first photographing operation and a second photographing operation successively to acquire a signal that can be used to generate a recording image, wherein the first image sensor includes a plurality of microlenses and a plurality of pixel portions each including a plurality of photoelectric conversion portions, wherein each of the plurality of pixel portions corresponds to each microlens and a second image sensor that is different from the first image sensor, wherein the second image sensor receives a pair of light fluxes of an image re-formed on a predetermined focal plane of an imaging optical system, the program comprising:
 computer-executable instructions for performing first focal point detection processing and second focal point detection processing successively, wherein the first focal point detection processing is operated between the first photographing operation and the second focal point detection processing, and wherein the second focal point detection processing is operated between the first focal point detection processing and the second photographing operation, wherein the first focal point detection processing and the second focal point detection processing are calculation of defocus amount, wherein the second focal point detection processing is performed by calculating the defocus amount by using the focal point detection signal acquired from the second image sensor; and 
 computer-executable instructions for controlling a first lens drive for driving focusing lens based on a result obtained through the first focal point detection processing, and controlling a second lens drive for driving the focusing lens based on a result obtained through the second focal point detection processing, 
 wherein the first focal point detection processing is performed by using the signal acquired from the first image sensor in the first photographing operation, and 
 wherein the second focal point detection processing is performed by using a focal point detection signal acquired from the second image sensor, 
 wherein if an aperture value corresponding to the signal acquired from the first image sensor is equal to or less than a first aperture value, the processor controls the first lens drive based on a focal point detection result obtained through the first focal point detection processing.